Chapter 12. Diagnostics214 PACSystems* RX7i & RX3i TCP/IP Ethernet Communications User Manual GFK-2224QController Fault User ActionModule state doesn’t permitComm_Req; discardedCOMMREQ received when Ethernet Interface cannot process COMMREQ.Make sure Ethernet Interface is configured and online. Error may occur ifthe logic application is sending COMMREQs faster than the EthernetInterface can process them. Reduce the rate at which COMMREQs are sent.Unsupported feature inconfigurationPLC firmware does not support Ethernet communications software orattempt has been made to configure a feature not supported by theEthernet Interface. Check CPU and Ethernet Interface revisions, orderupgrade kit for CPU and/or Ethernet Interface.Can’t locate remote node;discarded requestA specified remote device does not exist on the network. Check that theremote device IP address is correct and that the remote device isfunctioning properly.Mailbox Queue full – Comm_reqabortedThe CPU is attempting to send COMMREQs faster than the EthernetInterface can receive them. The PLC logic program should retry theCOMMREQ after a short delay. If the condition persists, the logic applicationshould be revised to reduce the rate at which it sends COMMREQs to theEthernet Interface.Non-critical CPU software event The CPU is attempting to send mail messages faster than they can beretrieved by the Ethernet Interface; the messages are discarded. This canresult in subsequent “Backplane communications with controller fault; lostrequest” faults.12.6 Monitoring the Ethernet Interface Status BitsThe Ethernet Interface status bits occupy a single block of memory, which is specified when the EthernetInterface is configured. The Ethernet Interface updates the status bits in the CPU once each controller scan.These bits can be used to prevent initiation of a COMM_REQ function when certain errors occur or to signal aproblem on an established channel.The first 16 bits of the block are the LAN Interface Status (LIS) bits. The next 64 bits are Channel Status bits (2 foreach channel). If the LAN Interface OK bit (bit 16) is not set, the other status bits are invalid.Note: The original information is located in GFK-2224L, TCP/IP Ethernet Communications forPACSystems RX3i and RX7i from June 2013.Note: For CPE330:LAN1 is the LAN (NIC) that contains the unswitched port in the CPE330. This isthe port similar to the CPE310. This port negotiates up to 1 Gbps. LAN2 is the LAN (NIC)that contains the switched ports in the CPE330. There are 2 ports in this LAN. These portsnegotiate up to 1 Gbps.
